This textbook offers a survey of all the major microcomputer operating systems through real-world case studies, annotated illustrations, and step-by-step tutorials and projects. It is designed for IT students who want to learn how to install, configure, and troubleshoot operating systems. This book will teach the basic functions of an operating system, such as the graphical user interface, memory management, device management, and file management. It also explains how to install, configure, and troubleshoot each of the major microcomputer operating systems, including DOS, Windows, Macintosh, UNIX, and, Linux, as well as explain the purpose of operating systems in different hardware environments, such as microcomputers and networks.